1. Technical Field
The invention relates to semiconductors and the fabrication thereof. In particular, the invention relates to contact and/or imprint lithography used to define one or both of micro-scale and nano-scale structures during semiconductor fabrication.
2. Description of Related Art
Photographic contact lithography and imprint lithography are examples of two lithography methodologies for defining micro-scale and nano-scale structures that generally involve direct contact between a patterning tool (e.g., mask, mold, template, etc.) and a substrate on which the structures are to be fabricated. In particular, during contact lithography, the patterning tool (i.e., mask) is aligned with and then brought in contact with the substrate or a pattern receiving layer of the substrate. Similarly, in imprint lithography, the patterning tool (i.e., mold) is aligned with the substrate after which the pattern is printed on or impressed into a receiving surface of the substrate. With either method, alignment between the patterning tool and the substrate general involves holding the patterning tool a small distance above the substrate while lateral and rotational adjustments (e.g., x-y translation and/or angular rotation) are made to a relative position of the tool and/or substrate. The patterning tool is then brought in contact with the substrate to perform the lithographic patterning.
In both of contact lithography and imprint lithography, an ultimate alignment accuracy as well as an achievable patterning resolution may be adversely affected by a degree to which the patterning tool and substrate are both mutually parallel and proximal during the alignment process. In addition, alignment accuracy may suffer as a result of drift or slip in the relative positioning of the aligned patterning tool and substrate that may occur as the tool is brought into contact with the substrate following alignment.
Accordingly, it would be desirable to have an approach to providing and maintaining a relatively parallel and proximal relationship between the patterning tool and the substrate during lateral and rotational alignment. Furthermore, it would be useful to provide a way of minimizing alignment drift and/or slip during contacting of the patterning tool and substrate following alignment. Such an approach would solve a long-standing need in the areas of contact lithography and imprint lithography.